Commit db0dd3a480
Changed files (1)
lib
std
lib/std/Io/EventLoop.zig
@@ -9,26 +9,25 @@ const IoUring = std.os.linux.IoUring;
gpa: Allocator,
mutex: std.Thread.Mutex,
-cond: std.Thread.Condition,
queue: std.DoublyLinkedList(void),
+/// Atomic copy of queue.len
+queue_len: usize,
free: std.DoublyLinkedList(void),
-main_context: Context,
-exit_awaiter: ?*Fiber,
+main_fiber: Fiber,
+idle_count: usize,
threads: std.ArrayListUnmanaged(Thread),
-/// 1 bit per thread, same order as `thread_index`.
-idle_iourings: []usize,
+exiting: bool,
threadlocal var thread_index: u32 = undefined;
/// Empirically saw 10KB being used by the self-hosted backend for logging.
-const idle_stack_size = 32 * 1024;
+const idle_stack_size = 64 * 1024;
const io_uring_entries = 64;
const Thread = struct {
thread: std.Thread,
idle_context: Context,
- current_idle_context: *Context,
current_context: *Context,
io_uring: IoUring,
@@ -103,98 +102,92 @@ pub fn io(el: *EventLoop) Io {
}
pub fn init(el: *EventLoop, gpa: Allocator) !void {
- const n_threads: usize = @max((std.Thread.getCpuCount() catch 1), 1);
- const threads_bytes = n_threads * @sizeOf(Thread);
- const idle_context_offset = std.mem.alignForward(usize, threads_bytes, @alignOf(Context));
- const idle_stack_end_offset = std.mem.alignForward(usize, idle_context_offset + idle_stack_size, std.heap.page_size_max);
- const allocated_slice = try gpa.alignedAlloc(u8, @max(@alignOf(Thread), @alignOf(Context)), idle_stack_end_offset);
+ const threads_size = @max(std.Thread.getCpuCount() catch 1, 1) * @sizeOf(Thread);
+ const idle_stack_end_offset = std.mem.alignForward(usize, threads_size + idle_stack_size, std.heap.page_size_max);
+ const allocated_slice = try gpa.alignedAlloc(u8, @alignOf(Thread), idle_stack_end_offset);
errdefer gpa.free(allocated_slice);
- const idle_iourings = try gpa.alloc(usize, (n_threads + @bitSizeOf(usize) - 1) / @bitSizeOf(usize));
- errdefer gpa.free(idle_iourings);
- @memset(idle_iourings, 0);
el.* = .{
.gpa = gpa,
.mutex = .{},
- .cond = .{},
.queue = .{},
+ .queue_len = 0,
.free = .{},
- .main_context = undefined,
- .exit_awaiter = null,
- .threads = .initBuffer(@ptrCast(allocated_slice[0..threads_bytes])),
- .idle_iourings = idle_iourings,
+ .main_fiber = undefined,
+ .idle_count = 0,
+ .threads = .initBuffer(@ptrCast(allocated_slice[0..threads_size])),
+ .exiting = false,
};
+ thread_index = 0;
const main_thread = el.threads.addOneAssumeCapacity();
main_thread.io_uring = try IoUring.init(io_uring_entries, 0);
- const main_idle_context: *Context = @alignCast(std.mem.bytesAsValue(Context, allocated_slice[idle_context_offset..][0..@sizeOf(Context)]));
- const idle_stack_end: [*]align(@max(@alignOf(Thread), @alignOf(Context))) usize = @alignCast(@ptrCast(allocated_slice[idle_stack_end_offset..].ptr));
+ const idle_stack_end: [*]usize = @alignCast(@ptrCast(allocated_slice[idle_stack_end_offset..].ptr));
(idle_stack_end - 1)[0..1].* = .{@intFromPtr(el)};
- main_idle_context.* = .{
+ main_thread.idle_context = .{
.rsp = @intFromPtr(idle_stack_end - 1),
.rbp = 0,
.rip = @intFromPtr(&mainIdleEntry),
};
- std.log.debug("created main idle {*}", .{main_idle_context});
- main_thread.current_idle_context = main_idle_context;
- std.log.debug("created main {*}", .{&el.main_context});
- main_thread.current_context = &el.main_context;
+ std.log.debug("created main idle {*}", .{&main_thread.idle_context});
+ std.log.debug("created main {*}", .{&el.main_fiber});
+ main_thread.current_context = &el.main_fiber.context;
}
pub fn deinit(el: *EventLoop) void {
assert(el.queue.len == 0); // pending async
- el.yield(null, &el.exit_awaiter);
+ el.yield(null, .exit);
while (el.free.pop()) |free_node| {
const free_fiber: *Fiber = @alignCast(@fieldParentPtr("queue_node", free_node));
el.gpa.free(free_fiber.allocatedSlice());
}
- const idle_context_offset = std.mem.alignForward(usize, el.threads.capacity * @sizeOf(Thread), @alignOf(Context));
- const idle_stack_end = std.mem.alignForward(usize, idle_context_offset + idle_stack_size, std.heap.page_size_max);
- const allocated_ptr: [*]align(@max(@alignOf(Thread), @alignOf(Context))) u8 = @alignCast(@ptrCast(el.threads.items.ptr));
+ const idle_stack_end_offset = std.mem.alignForward(usize, el.threads.capacity * @sizeOf(Thread) + idle_stack_size, std.heap.page_size_max);
+ const allocated_ptr: [*]align(@alignOf(Thread)) u8 = @alignCast(@ptrCast(el.threads.items.ptr));
for (el.threads.items[1..]) |*thread| thread.thread.join();
- el.gpa.free(allocated_ptr[0..idle_stack_end]);
+ el.gpa.free(allocated_ptr[0..idle_stack_end_offset]);
}
-const PendingTask = union(enum) {
- none,
- register_awaiter: *?*Fiber,
- io_uring_submit: *IoUring,
-};
-
-fn yield(el: *EventLoop, optional_fiber: ?*Fiber, pending_task: PendingTask) void {
+fn yield(el: *EventLoop, optional_fiber: ?*Fiber, pending_task: SwitchMessage.PendingTask) void {
const thread: *Thread = &el.threads.items[thread_index];
const ready_context: *Context = ready_context: {
const ready_fiber: *Fiber = optional_fiber orelse if (ready_node: {
el.mutex.lock();
defer el.mutex.unlock();
- break :ready_node el.queue.pop();
+ const ready_node = el.queue.pop();
+ @atomicStore(usize, &el.queue_len, el.queue.len, .unordered);
+ break :ready_node ready_node;
}) |ready_node|
@alignCast(@fieldParentPtr("queue_node", ready_node))
else
- break :ready_context thread.current_idle_context;
+ break :ready_context &thread.idle_context;
break :ready_context &ready_fiber.context;
};
const message: SwitchMessage = .{
- .prev_context = thread.current_context,
- .ready_context = ready_context,
+ .contexts = .{
+ .prev = thread.current_context,
+ .ready = ready_context,
+ },
.pending_task = pending_task,
};
- std.log.debug("switching from {*} to {*}", .{ message.prev_context, message.ready_context });
+ std.log.debug("switching from {*} to {*}", .{ message.contexts.prev, message.contexts.ready });
contextSwitch(&message).handle(el);
}
fn schedule(el: *EventLoop, fiber: *Fiber) void {
- el.mutex.lock();
- el.queue.append(&fiber.queue_node);
- //for (el.idle_iourings) |*int| {
- // const idler_subset = @atomicLoad(usize, int, .unordered);
- // if (idler_subset == 0) continue;
- //
- //}
- if (el.idle_count > 0) {
- el.mutex.unlock();
- el.cond.signal();
+ if (idle_count: {
+ el.mutex.lock();
+ defer el.mutex.unlock();
+ el.queue.append(&fiber.queue_node);
+ @atomicStore(usize, &el.queue_len, el.queue.len, .unordered);
+ break :idle_count el.idle_count;
+ } > 0) {
+ _ = std.os.linux.futex2_wake(&el.queue_len, std.math.maxInt(usize), 1, switch (@bitSizeOf(usize)) {
+ 8 => std.os.linux.FUTEX2.SIZE_U8,
+ 16 => std.os.linux.FUTEX2.SIZE_U16,
+ 32 => std.os.linux.FUTEX2.SIZE_U32,
+ 64 => std.os.linux.FUTEX2.SIZE_U64,
+ else => @compileError("unsupported @sizeOf(usize)"),
+ } | std.os.linux.FUTEX2.PRIVATE); // TODO: io_uring
return;
}
- defer el.mutex.unlock();
if (el.threads.items.len == el.threads.capacity) return;
const thread = el.threads.addOneAssumeCapacity();
thread.thread = std.Thread.spawn(.{
@@ -216,64 +209,101 @@ fn recycle(el: *EventLoop, fiber: *Fiber) void {
fn mainIdle(el: *EventLoop, message: *const SwitchMessage) callconv(.withStackAlign(.c, @max(@alignOf(Thread), @alignOf(Context)))) noreturn {
message.handle(el);
- el.yield(el.idle(), null);
+ el.idle();
+ el.yield(&el.main_fiber, .nothing);
unreachable; // switched to dead fiber
}
fn threadEntry(el: *EventLoop, index: usize) void {
- thread_index = index;
+ thread_index = @intCast(index);
const thread: *Thread = &el.threads.items[index];
std.log.debug("created thread idle {*}", .{&thread.idle_context});
thread.io_uring = IoUring.init(io_uring_entries, 0) catch |err| {
std.log.warn("exiting worker thread during init due to io_uring init failure: {s}", .{@errorName(err)});
return;
};
- thread.current_idle_context = &thread.idle_context;
thread.current_context = &thread.idle_context;
- _ = el.idle();
+ el.idle();
}
-fn idle(el: *EventLoop) *Fiber {
+const UserData = enum(u64) {
+ queue_len_futex_wait,
+ _,
+};
+
+fn idle(el: *EventLoop) void {
const thread: *Thread = &el.threads.items[thread_index];
- // The idle fiber only runs on one thread.
const iou = &thread.io_uring;
var cqes_buffer: [io_uring_entries]std.os.linux.io_uring_cqe = undefined;
+ var futex_is_scheduled: bool = false;
while (true) {
- el.yield(null, null);
- if (@atomicLoad(?*Fiber, &el.exit_awaiter, .acquire)) |exit_awaiter| {
- el.cond.broadcast();
- return exit_awaiter;
- }
- // TODO add uring to bit set
- const n = iou.copy_cqes(&cqes_buffer, 1) catch @panic("TODO handle copy_cqes error");
- const cqes = cqes_buffer[0..n];
- for (cqes) |cqe| {
- const fiber: *Fiber = @ptrFromInt(cqe.user_data);
- const res: *i32 = @ptrCast(@alignCast(fiber.resultPointer()));
- res.* = cqe.res;
- el.schedule(fiber);
+ el.yield(null, .nothing);
+ if (@atomicLoad(bool, &el.exiting, .acquire)) return;
+ if (!futex_is_scheduled) {
+ const sqe = getSqe(&thread.io_uring);
+ sqe.prep_rw(.FUTEX_WAIT, switch (@bitSizeOf(usize)) {
+ 8 => std.os.linux.FUTEX2.SIZE_U8,
+ 16 => std.os.linux.FUTEX2.SIZE_U16,
+ 32 => std.os.linux.FUTEX2.SIZE_U32,
+ 64 => std.os.linux.FUTEX2.SIZE_U64,
+ else => @compileError("unsupported @sizeOf(usize)"),
+ } | std.os.linux.FUTEX2.PRIVATE, @intFromPtr(&el.queue_len), 0, 0);
+ sqe.addr3 = std.math.maxInt(u64);
+ sqe.user_data = @intFromEnum(UserData.queue_len_futex_wait);
+ futex_is_scheduled = true;
}
+ _ = iou.submit_and_wait(1) catch |err| switch (err) {
+ error.SignalInterrupt => 0,
+ else => @panic(@errorName(err)),
+ };
+ for (cqes_buffer[0 .. iou.copy_cqes(&cqes_buffer, 1) catch |err| switch (err) {
+ error.SignalInterrupt => 0,
+ else => @panic(@errorName(err)),
+ }]) |cqe| switch (@as(UserData, @enumFromInt(cqe.user_data))) {
+ .queue_len_futex_wait => futex_is_scheduled = false,
+ _ => {
+ const fiber: *Fiber = @ptrFromInt(cqe.user_data);
+ const res: *i32 = @ptrCast(@alignCast(fiber.resultPointer()));
+ res.* = cqe.res;
+ el.schedule(fiber);
+ },
+ };
}
}
-const SwitchMessage = extern struct {
- prev_context: *Context,
- ready_context: *Context,
+const SwitchMessage = struct {
+ contexts: extern struct {
+ prev: *Context,
+ ready: *Context,
+ },
pending_task: PendingTask,
+ const PendingTask = union(enum) {
+ nothing,
+ register_awaiter: *?*Fiber,
+ exit,
+ };
+
fn handle(message: *const SwitchMessage, el: *EventLoop) void {
const thread: *Thread = &el.threads.items[thread_index];
- thread.current_context = message.ready_context;
+ thread.current_context = message.contexts.ready;
switch (message.pending_task) {
- .none => {},
+ .nothing => {},
.register_awaiter => |awaiter| {
- const prev_fiber: *Fiber = @alignCast(@fieldParentPtr("context", message.prev_context));
+ const prev_fiber: *Fiber = @alignCast(@fieldParentPtr("context", message.contexts.prev));
if (@atomicRmw(?*Fiber, awaiter, .Xchg, prev_fiber, .acq_rel) == Fiber.finished) el.schedule(prev_fiber);
},
- .io_uring_submit => |iou| {
- _ = iou.flush_sq();
- // TODO: determine whether this return value should be used
+ .exit => {
+ @atomicStore(bool, &el.exiting, true, .unordered);
+ @atomicStore(usize, &el.queue_len, std.math.maxInt(usize), .release);
+ _ = std.os.linux.futex2_wake(&el.queue_len, std.math.maxInt(usize), std.math.maxInt(i32), switch (@bitSizeOf(usize)) {
+ 8 => std.os.linux.FUTEX2.SIZE_U8,
+ 16 => std.os.linux.FUTEX2.SIZE_U16,
+ 32 => std.os.linux.FUTEX2.SIZE_U32,
+ 64 => std.os.linux.FUTEX2.SIZE_U64,
+ else => @compileError("unsupported @sizeOf(usize)"),
+ } | std.os.linux.FUTEX2.PRIVATE); // TODO: use io_uring
},
}
}
@@ -289,7 +319,7 @@ const Context = switch (builtin.cpu.arch) {
};
inline fn contextSwitch(message: *const SwitchMessage) *const SwitchMessage {
- return switch (builtin.cpu.arch) {
+ return @fieldParentPtr("contexts", switch (builtin.cpu.arch) {
.x86_64 => asm volatile (
\\ movq 0(%%rsi), %%rax
\\ movq 8(%%rsi), %%rcx
@@ -301,8 +331,8 @@ inline fn contextSwitch(message: *const SwitchMessage) *const SwitchMessage {
\\ movq 8(%%rcx), %%rbp
\\ jmpq *16(%%rcx)
\\0:
- : [received_message] "={rsi}" (-> *const SwitchMessage),
- : [message_to_send] "{rsi}" (message),
+ : [received_message] "={rsi}" (-> *const @FieldType(SwitchMessage, "contexts")),
+ : [message_to_send] "{rsi}" (&message.contexts),
: "rax", "rcx", "rdx", "rbx", "rdi", //
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", //
"mm0", "mm1", "mm2", "mm3", "mm4", "mm5", "mm6", "mm7", //
@@ -313,7 +343,7 @@ inline fn contextSwitch(message: *const SwitchMessage) *const SwitchMessage {
"fpsr", "fpcr", "mxcsr", "rflags", "dirflag", "memory"
),
else => |arch| @compileError("unimplemented architecture: " ++ @tagName(arch)),
- };
+ });
}
fn mainIdleEntry() callconv(.naked) void {
@@ -401,7 +431,7 @@ const AsyncClosure = struct {
std.log.debug("{*} performing async", .{closure.fiber});
closure.start(closure.contextPointer(), closure.fiber.resultPointer());
const awaiter = @atomicRmw(?*Fiber, &closure.fiber.awaiter, .Xchg, Fiber.finished, .acq_rel);
- closure.event_loop.yield(awaiter, null);
+ closure.event_loop.yield(awaiter, .nothing);
unreachable; // switched to dead fiber
}
};
@@ -409,17 +439,93 @@ const AsyncClosure = struct {
pub fn @"await"(userdata: ?*anyopaque, any_future: *std.Io.AnyFuture, result: []u8) void {
const event_loop: *EventLoop = @alignCast(@ptrCast(userdata));
const future_fiber: *Fiber = @alignCast(@ptrCast(any_future));
- if (@atomicLoad(?*Fiber, &future_fiber.awaiter, .acquire) != Fiber.finished) event_loop.yield(null, &future_fiber.awaiter);
+ if (@atomicLoad(?*Fiber, &future_fiber.awaiter, .acquire) != Fiber.finished) event_loop.yield(null, .{ .register_awaiter = &future_fiber.awaiter });
@memcpy(result, future_fiber.resultPointer());
event_loop.recycle(future_fiber);
}
pub fn createFile(userdata: ?*anyopaque, dir: std.fs.Dir, sub_path: []const u8, flags: std.fs.File.CreateFlags) std.fs.File.OpenError!std.fs.File {
- _ = userdata;
- _ = dir;
- _ = sub_path;
- _ = flags;
- @panic("TODO");
+ const el: *EventLoop = @ptrCast(@alignCast(userdata));
+
+ const posix = std.posix;
+ const sub_path_c = try posix.toPosixPath(sub_path);
+
+ var os_flags: posix.O = .{
+ .ACCMODE = if (flags.read) .RDWR else .WRONLY,
+ .CREAT = true,
+ .TRUNC = flags.truncate,
+ .EXCL = flags.exclusive,
+ };
+ if (@hasField(posix.O, "LARGEFILE")) os_flags.LARGEFILE = true;
+ if (@hasField(posix.O, "CLOEXEC")) os_flags.CLOEXEC = true;
+
+ // Use the O locking flags if the os supports them to acquire the lock
+ // atomically. Note that the NONBLOCK flag is removed after the openat()
+ // call is successful.
+ const has_flock_open_flags = @hasField(posix.O, "EXLOCK");
+ if (has_flock_open_flags) switch (flags.lock) {
+ .none => {},
+ .shared => {
+ os_flags.SHLOCK = true;
+ os_flags.NONBLOCK = flags.lock_nonblocking;
+ },
+ .exclusive => {
+ os_flags.EXLOCK = true;
+ os_flags.NONBLOCK = flags.lock_nonblocking;
+ },
+ };
+ const have_flock = @TypeOf(posix.system.flock) != void;
+
+ if (have_flock and !has_flock_open_flags and flags.lock != .none) {
+ @panic("TODO");
+ }
+
+ if (has_flock_open_flags and flags.lock_nonblocking) {
+ @panic("TODO");
+ }
+
+ const thread: *Thread = &el.threads.items[thread_index];
+ const iou = &thread.io_uring;
+ const sqe = getSqe(iou);
+ const fiber = thread.currentFiber();
+
+ sqe.prep_openat(dir.fd, &sub_path_c, os_flags, flags.mode);
+ sqe.user_data = @intFromPtr(fiber);
+
+ el.yield(null, .nothing);
+
+ const result: *i32 = @alignCast(@ptrCast(fiber.resultPointer()[0..@sizeOf(posix.fd_t)]));
+ const rc = result.*;
+ switch (errno(rc)) {
+ .SUCCESS => return .{ .handle = rc },
+ .INTR => @panic("TODO is this reachable?"),
+ .CANCELED => @panic("TODO figure out how this error code fits into things"),
+
+ .FAULT => unreachable,
+ .INVAL => return error.BadPathName,
+ .BADF => unreachable,
+ .ACCES => return error.AccessDenied,
+ .FBIG => return error.FileTooBig,
+ .OVERFLOW => return error.FileTooBig,
+ .ISDIR => return error.IsDir,
+ .LOOP => return error.SymLinkLoop,
+ .MFILE => return error.ProcessFdQuotaExceeded,
+ .NAMETOOLONG => return error.NameTooLong,
+ .NFILE => return error.SystemFdQuotaExceeded,
+ .NODEV => return error.NoDevice,
+ .NOENT => return error.FileNotFound,
+ .NOMEM => return error.SystemResources,
+ .NOSPC => return error.NoSpaceLeft,
+ .NOTDIR => return error.NotDir,
+ .PERM => return error.PermissionDenied,
+ .EXIST => return error.PathAlreadyExists,
+ .BUSY => return error.DeviceBusy,
+ .OPNOTSUPP => return error.FileLocksNotSupported,
+ .AGAIN => return error.WouldBlock,
+ .TXTBSY => return error.FileBusy,
+ .NXIO => return error.NoDevice,
+ else => |err| return posix.unexpectedErrno(err),
+ }
}
pub fn openFile(userdata: ?*anyopaque, dir: std.fs.Dir, sub_path: []const u8, flags: std.fs.File.OpenFlags) std.fs.File.OpenError!std.fs.File {
@@ -476,7 +582,7 @@ pub fn openFile(userdata: ?*anyopaque, dir: std.fs.Dir, sub_path: []const u8, fl
sqe.prep_openat(dir.fd, &sub_path_c, os_flags, 0);
sqe.user_data = @intFromPtr(fiber);
- el.yield(null, .{ .io_uring_submit = iou });
+ el.yield(null, .nothing);
const result: *i32 = @alignCast(@ptrCast(fiber.resultPointer()[0..@sizeOf(posix.fd_t)]));
const rc = result.*;
@@ -510,8 +616,6 @@ pub fn openFile(userdata: ?*anyopaque, dir: std.fs.Dir, sub_path: []const u8, fl
.NXIO => return error.NoDevice,
else => |err| return posix.unexpectedErrno(err),
}
-
- return .{ .handle = result.* };
}
fn errno(signed: i32) std.posix.E {
@@ -524,21 +628,109 @@ fn getSqe(iou: *IoUring) *std.os.linux.io_uring_sqe {
}
pub fn closeFile(userdata: ?*anyopaque, file: std.fs.File) void {
- _ = userdata;
- _ = file;
- @panic("TODO");
+ const el: *EventLoop = @ptrCast(@alignCast(userdata));
+
+ const posix = std.posix;
+
+ const thread: *Thread = &el.threads.items[thread_index];
+ const iou = &thread.io_uring;
+ const sqe = getSqe(iou);
+ const fiber = thread.currentFiber();
+
+ sqe.prep_close(file.handle);
+ sqe.user_data = @intFromPtr(fiber);
+
+ el.yield(null, .nothing);
+
+ const result: *i32 = @alignCast(@ptrCast(fiber.resultPointer()[0..@sizeOf(posix.fd_t)]));
+ const rc = result.*;
+ switch (errno(rc)) {
+ .SUCCESS => return,
+ .INTR => @panic("TODO is this reachable?"),
+ .CANCELED => @panic("TODO figure out how this error code fits into things"),
+
+ .BADF => unreachable, // Always a race condition.
+ else => return,
+ }
}
pub fn read(userdata: ?*anyopaque, file: std.fs.File, buffer: []u8) std.fs.File.ReadError!usize {
- _ = userdata;
- _ = file;
- _ = buffer;
- @panic("TODO");
+ const el: *EventLoop = @ptrCast(@alignCast(userdata));
+
+ const posix = std.posix;
+
+ const thread: *Thread = &el.threads.items[thread_index];
+ const iou = &thread.io_uring;
+ const sqe = getSqe(iou);
+ const fiber = thread.currentFiber();
+
+ sqe.prep_read(file.handle, buffer, std.math.maxInt(u64));
+ sqe.user_data = @intFromPtr(fiber);
+
+ el.yield(null, .nothing);
+
+ const result: *i32 = @alignCast(@ptrCast(fiber.resultPointer()[0..@sizeOf(posix.fd_t)]));
+ const rc = result.*;
+ switch (errno(rc)) {
+ .SUCCESS => return @as(u32, @bitCast(rc)),
+ .INTR => @panic("TODO is this reachable?"),
+ .CANCELED => @panic("TODO figure out how this error code fits into things"),
+
+ .INVAL => unreachable,
+ .FAULT => unreachable,
+ .NOENT => return error.ProcessNotFound,
+ .AGAIN => return error.WouldBlock,
+ .BADF => return error.NotOpenForReading, // Can be a race condition.
+ .IO => return error.InputOutput,
+ .ISDIR => return error.IsDir,
+ .NOBUFS => return error.SystemResources,
+ .NOMEM => return error.SystemResources,
+ .NOTCONN => return error.SocketNotConnected,
+ .CONNRESET => return error.ConnectionResetByPeer,
+ .TIMEDOUT => return error.ConnectionTimedOut,
+ else => |err| return posix.unexpectedErrno(err),
+ }
}
pub fn write(userdata: ?*anyopaque, file: std.fs.File, buffer: []const u8) std.fs.File.WriteError!usize {
- _ = userdata;
- _ = file;
- _ = buffer;
- @panic("TODO");
+ const el: *EventLoop = @ptrCast(@alignCast(userdata));
+
+ const posix = std.posix;
+
+ const thread: *Thread = &el.threads.items[thread_index];
+ const iou = &thread.io_uring;
+ const sqe = getSqe(iou);
+ const fiber = thread.currentFiber();
+
+ sqe.prep_write(file.handle, buffer, std.math.maxInt(u64));
+ sqe.user_data = @intFromPtr(fiber);
+
+ el.yield(null, .nothing);
+
+ const result: *i32 = @alignCast(@ptrCast(fiber.resultPointer()[0..@sizeOf(posix.fd_t)]));
+ const rc = result.*;
+ switch (errno(rc)) {
+ .SUCCESS => return @as(u32, @bitCast(rc)),
+ .INTR => @panic("TODO is this reachable?"),
+ .CANCELED => @panic("TODO figure out how this error code fits into things"),
+
+ .INVAL => return error.InvalidArgument,
+ .FAULT => unreachable,
+ .NOENT => return error.ProcessNotFound,
+ .AGAIN => return error.WouldBlock,
+ .BADF => return error.NotOpenForWriting, // can be a race condition.
+ .DESTADDRREQ => unreachable, // `connect` was never called.
+ .DQUOT => return error.DiskQuota,
+ .FBIG => return error.FileTooBig,
+ .IO => return error.InputOutput,
+ .NOSPC => return error.NoSpaceLeft,
+ .ACCES => return error.AccessDenied,
+ .PERM => return error.PermissionDenied,
+ .PIPE => return error.BrokenPipe,
+ .CONNRESET => return error.ConnectionResetByPeer,
+ .BUSY => return error.DeviceBusy,
+ .NXIO => return error.NoDevice,
+ .MSGSIZE => return error.MessageTooBig,
+ else => |err| return posix.unexpectedErrno(err),
+ }
}